retention has everything to do with membership price, content quality, and frequency of updates.
if it's a clean personable member area with frequent quality updates you
will retain, build a loyal fanbase, and get word of mouth. word of mouth spread at the office water cooler is the best converting traffic one can get, hehe.
i don't have enough experience with the reality style niche you are referring too to be of much help but i do have a lot of paysite experience. i would be interested to see the reality niche ratio #'s too. anyone?